Rising oceans?

Should we spend billions of dollars on something that even the scientists can't agree will happen? Some say the ocean will rise 10 inches in the next hundred years, some say 7 feet in the next thousand years.

In June, New York City Mayor Michael Bloomberg proposed a $20 billion flood barrier system that would protect the city from future hurricanes and rising sea levels.

Florida communities are also considering multimillion-dollar proposals to modernize their flood prevention systems.

This is an interesting thought... even without rising seas... especially looking toward New Orleans and the Jersey Shore.. Both of which haven't recovered.
I am from the westcoast, and we are always running tsunami drills etc... trouble is some of the gradeschools and even the highschool I attended in my hometown would be underwater if a large enough tsunami hit.
I do not mind some precautions.. however, there is always going to have to be figured in "acceptable" loss... We can not control the earth.. from freak tornadoes to tsunami's each area has it's issue... At some point it isn't even a matter of cost it is a matter of doability.. some things we just do not have the smarts to pull off... this isn't a scifi movie or show like stargate atlantis where we can sink our society under the water in a bubble.. etc.

I am just not as engineering inclined as I would like to know if the proposals are actually worth it. Or is it better to consider a relocation program.

Here's a forward-looking article from a more global perspective that takes in not just the impact of rising ocean levels but greenhouse gas emissions and global warming as a result of rising water levels. The potential costs are staggering.

The Japanese tsunami walls and storm gates weren't nearly as effective as they were hoped to be. Granted, that was a massive tsunami, and it struck so quickly that some of the storm gates weren't able to be closed in time, but I don't think putting up walls along our coastline is the answer. And I don't think spending $20 billion to protect one city against another "storm of the century" is a wise idea. Should we invest some money into upgrading the infrastructure of some major coastal cities to better withstand another flood? Yes, probably we should, but it should be more along the lines of better ways to close off the subway system, pumping systems to drain water out of low-lying areas faster, and restoring some of the natural breakwaters that used to exist along the coastlines but were removed to build harbors & shipping channels. And requiring any new building, or any building that does significant renovation work, to completely waterproof its ground floor wouldn't be a bad idea.